This project focuses on the late complications of therapy for cancer in childhood or adolescence. Mortality and morbidity, especially second cancers, and fertility of long-term survivors of childhood and adolescent cancer, are studied for information on the carcinogenicity, gonadal toxicity, and possible mutagenicity of cancer treatment, to uncover hereditary patterns of cancer, and to delineate the factors that predispose to second cancers. Current phases include analysis of data collected from interviews with 593 survivors of leukemia in childhood and 409 of their brothers and sisters as controls; analysis of data from a smaller study at NIH's Clinical Center of fertility in women treated over 20 years ago, and first reported in 1976; and an imaging study of women who had Wilms' tumor to determine the prevalence of uterine anomalies. With data from the Five Center Study, a large interview study with survivors of many types of childhood and adolescent cancer, we are studying the late mortality of long-term survivors, and how alterations in the timing of menarche affects timing of menopause.